) (02/25/89)
Is there a way to exports system-variables from subshell, running in background
to the main shell?
I tried and tried and tried... but with no results... :-(
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Kianusch SAYAH-KARADJI |/ | / \ | \ | | | \___ | |____|
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======================= | \ _|_ / \ | \| \___/ ____/ \___/ | |gwyn@smoke.BRL.MIL (Doug Gwyn ) (02/26/89)
In article <424@unicom.UUCP> sayah_k@unicom.UUCP (KIANUSCH... Yes, Kianusch himself !!!) writes: >Is there a way to exports system-variables from subshell, running in background >to the main shell? There's no (simple, portable, supported) way to alter a process's environment variables from a subprocess. The best you can do is to write the information into a pipe, file, FIFO, or some such and make the parent shell pick up that information. Without knowing exactly why you want to do this, I cannot give more specific advice. It's possible that you're trying to do something the hard way...
leo@philmds.UUCP (Leo de Wit) (02/26/89)
In article <424@unicom.UUCP> sayah_k@unicom.UUCP (KIANUSCH... Yes, Kianusch himself !!!) writes: |Is there a way to exports system-variables from subshell, running in background |to the main shell? | |I tried and tried and tried... but with no results... :-( | You haven't tried the following (assuming you don't need signal 5 in the main shell). You can use it in all kinds of ways to communicate between a parent and its child shell; I saw the idea first presented by Maarten Litmaath to implement a 'cd with prompt-to-path conversion' kind of cd alias for the Bourne shell. Script started on Sun Feb 26 13:51:22 1989 philmds> trap ". .readvar" 5 philmds> trap 5: . .readvar philmds> (echo "NEWVAR=newvalue export NEWVAR" >.readvar; kill -5 $$)& 19795 philmds> [1] Done ( echo "NEWVAR=newvalue export NEWVAR"; kill -5 $$ ) philmds> echo $NEWVAR philmds> echo $NEWVAR newvalue philmds> script done on Sun Feb 26 13:55:43 1989 Note the somewhat peculiar behaviour of the main shell: the trap seems to be honoured only after execution of the next command. Maybe someone else has a reasonable explanation of this? Leo.